Process of extracting potassium salts from feldspar.



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HENRY llill'IEl'BERG'-, JR., OF LOS ANGELES, CALIFORNIA, ASSIGNOR T0 CHEMICAL CONSTRUCTION COMPANY, 0F LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

0F EXTRACTIN G POTASSIUM SALTS FROM.' FELDSPAR.

No Brewing..

FIY` 77 7 v i 1 l r o am uvam/f. 'it may concern.'

Be it .known that I, HENRY BLUMENBERG, Jr.. a citizen oi' the YUnited States, residmg at Los Angeles, in the county of Los Ange- 'art for extracting potassium salts from feldspar and the like, but so far as I am aware, none of 'them have been a. commerclal success for the reason that the reagents used 1n the 'process are either'too expensive, or high temperatures are necessary to break up the feldspar to render the potassium saltsl available,

or the iihal process of separation involves iiltration and crystallization.

I have devised a process for extracting potassium salts from feldspar and the like which uses inexpensive reagents, avoids high temperatures, and produces a' product in which the potassium salts are present as` potassium sulfate, while the reinainder'of Vthe mass is insoluble. The soluble potassium sulfate may be usually extracted from the mass by the simple process of leaching.

My invention consists in the steps of the process hereinafter described and claimed.

I taire one part ouf feldspar, finely pulverizcd and passed through a 200 mesh screen, one part or' gypsum, linely pulverlzed, and

one part of acid sludge, the latter being av ell-known ily-product of the mineral Oil industry and containing from t0 50% of sulfuric acid. These ingredients are thoroughly mixed and form a thick, pasty mass. Then'iixture is heated in the presence of air for several hours to a temperature of The sulfuric aeid'of the acid 'f ge combines with the aluminum of the 'par to produce aluminum sulfate. It

is a pass oier the heated mass so that the carbonaceous material contained in the acid sludge will net reduce the sulfate produced to sulfide. produced. ille temperature is raisedloeyond the ilii-iseciation peint of the feldspar, re-

Speccation of Letters Patent.

lso advisable to use au excess of air to" When aluminum sulfate has beenv Patented Mar. 4, 1919.

Application filed .Tuly 23, 1917. Serial No. 182,250.

clinker, which can be easily broken up and the. potassium sulfate, which is the only solublesalt contained therein, may be easily leached out by means of Water, and then concentrated to a solid form by any preferred method. 1

The advantage of usi-ng the acid sludge is in utilizing an inexpensive'waste product 'wlnch contains sulfuric acid and carbonaceous material, the burningof the latter furnishingl the necessary heat units to carry on the reaction, which is superior to the use of calcium sulfate with feldspar alone.

Another advantage of my process over similar processes that use they sulfates and acid sulfates of the alkali metals, is that the` reaction is effected With a small amount of sulfuric acid or sulfates. In processes using sulfates, or acid sulfates of the alkali metals it is necessary to have at least from three to four parts of the acid sulfatein proportion to one part of the feldspar to effect a complete reduction of the latter. 1

I am fully aware that if the mixture of feldspar, calciumsulfate and acid sludge is calcined only up to 7000 C. that an aluminum potassium sulfate is produced (so-called potassium alum) which may be leached v.out and crystallized. 'f i f In my process, the only solubile salt th at is formed is potassium sulfate, as aluminum and calcium silicates are insoluble.

As will be readily seen, my process will be gisV useful in either making the potassium suli nection with -feldspan ib will be understood that other minerals or materials containing 1 odo sium sulfate and insoluble calcium aluminum silicate, and leaching the soluble potassium.

sulfate from the mass.

2. A process of extracting potassium from potassium containing materials, comprising mixing a potassium-containing material with a sulfate of an alkaline earth metal and acid sludge, heating the same in the presence of air to form a soluble potassium salt, and separating said potassium'salt from the mass.

In testimony whereof I have signed my name to this specification.

l HENRY BLUMENBERG, Jn. 

